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Discussion Starter · #1 ·
I have two sets of this style poly magnet. http://www.ebay.com/itm/3-PAIR-of-m...261097580197?pt=Slot_Cars&hash=item3ccaa0e6a5

I tried them with a Mean Green arm in two of my Autoworld 4 gear drag cars. They made my cars slower then the stock ceramic magnets. Im not sure how to ohm out the arms at all. I have a few other arms that I want to try but I thought I would check here first and see what everyone says. What arm would go best with these polys? Also I seen somewhere on how to test the pull of the magnets but cant find it at all. How did that go again?
 

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check the ohms on that arm. 6 OHMs is about the cutoff for a noticeable advantage from the polymer magnets. anything higher just slows down. also, what voltage are you running it on? and what amperage is available with that voltage?
you may get your best speed out of that chassis set up with Johhny Lightning/Auto World blue and white magnets anyway.
beware, there are sellers calling Auto World 15 OHM arms "mean green" and if one doesn't know better one might actually believe it.

if you have a meter, make sure the commutator is clean and touch the leads to 2 sections of the comm at a time. that will give you the ohms for that stack.
if you don't have a meter, there is no way.
as far as measuring magnet strength, I have been soundly criticized for my attempts at explaining before, so I will allow the critics to take on that chore.
 

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More Questions
Is the AW 4 gear armature different and not replaceable?
I've seen some comments "..will not work with New 4 gear chassis.."

Magnet strength
Are Tjet size poly magnets about the same strength as AW X trac?

thus +-16 ohm armatures (new AW and old TJET) work ok with AW and small powerful
magnets, but put a YellowJacket Arm with Poly magnets and get real POWER.
(big block in vega)

(time to get the magnum 1000 out)
 

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You can easily test the magnet strength by seeing how many small metal objects it will pick up, or use a ruler & compass where length away from the compass determines the strength or BRP makes a magnet matcher.

I am with AL, it takes a good arm & power supply to run poly's, and if you do make sure to keep an eye on the heat, Pancakes burn really easy.

Boosted
 

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cwbam, the 4 gear armatures rotate in the opposite direction of three gear chassis.
therefore if an advance in the timing has been set up for a three gear chassis it will be retarded for a 4 gear chassis. advance timing is good for high RPMs and long straights. retarded timing is good for tight twisty courses and give more torque but less top end.
so neutral timed arms will work equally well in all chassis.
 

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Discussion Starter · #7 ·
More Questions
Is the AW 4 gear armature different and not replaceable?
I've seen some comments "..will not work with New 4 gear chassis.."

Magnet strength
Are Tjet size poly magnets about the same strength as AW X trac?

thus +-16 ohm armatures (new AW and old TJET) work ok with AW and small powerful
magnets, but put a YellowJacket Arm with Poly magnets and get real POWER.
(big block in vega)

(time to get the magnum 1000 out)
You can change the arms in the autowrld 4 gear chassis. Just takes a little modding to the arm holes on both the top plate and chassis. I use one of these to take a little off the hole and test fit to see if it spins freely. http://www.dremel.com/en-us/Accessories/Pages/ProductDetail.aspx?pid=114

Thanks guys. Al the volts that where being ran where 22 volts for funny car and 24 volts for top fuel. My times with ceramic magnet where funny car .976 and top fuel 1.063. Times with poly magnets where funny car 1.036 and top fuel 1.227. Everything is stock on both cars but the arms and magnets. But I change the magnet back to the ceramic magnets when I got the cars back.
 

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TAZ

I used to do a lot poly mag racing with the AFX magnatraction cars.
Alpink is right on the money.

I used used mean greens (5.7 to 6.2 ohms) and custom winds down to about 3ohms. they were fast & fun!
 

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As with all hot-rod parts, fanciful dreams and unreasonable expectations usually boil down to simple facts. High zoop magnets require a properly matched armature and the experience to set up the ENTIRE chassis. Presuming you have good power and a matched controller, Polys still do not:

...select a good armature or balance it
...select a good chassis
...set the comm pressure
...lap the gear set and remove all drive train frictions
...select the correct pick up parts and dial them in
...identify the correct wheel and tire combinations
...tear it all down and start over

As Boosted noted, They WILL fizz armatures that dont muster up.
The bottom line is that the "optimum operational tuning window" tightens right up when working with polys, and thus the allowable margin for tuning error decreases accordingly.

Not trying to be a purveyor of gloom and doom here. Just trying to dispel the associated magic wand hyperbole that accompanys all hot rod parts.

...but like Mike said, when you get them (especially the Magnas) just right they will make ya giggle!
 

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Bill - well done. Couldn't have summed it up any better. :thumbsup:

My limited experience with polys on Mag Tractions is that by adding polys the top speed will drop but the torque goes way up, and obviously so does the traction.

I have a real burner that has the nacho magnets with a balanced and trued (OD turned down to about .655") 6-ohm tuffones arm. Man, is that thing fast and fun. Even with that big air gap those powerful magnets really react well with the arm!
 

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Discussion Starter · #13 ·
They where in my proxy drag cars. Where there are set rules for the arms. No dewinding no rewinds. Only can do balancing and polishing.
 

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POYL MAG

...select a good armature or balance it
JIM S

...select a good chassis
40 YEAR PLASTIC?

...set the comm pressure
? THERE GOES ANOTHER PIECE OF COPPER

...lap the gear set and remove all drive train frictions
YEAH SURE GET THE DREMEL OUT !!!!!

...select the correct pick up parts and dial them in
ANY GLUES YOU LIKE? FOR PIN AND DRIVE (AFTER PEENING)

fizz armatures that dont muster up.
WHAT TEMP IS TO HIGH 140*?

I'm a tjet hack neophyte , (? polyphyte?)


.
 

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I know this is an older thread, but... I have had the same issues here, the polys slowed down my car. I have tried them with a 4.6 ohm arm made specifically for a 4 gear chassis, the car is faster with the AW mags than with the polys. I am going to try some other arms and see what happens, I have one or two that will ohm out lower.

Can anyone tell me how low ohms I can go to with about 5 amps 24v for 2 lanes 1/8 mile?
How about the stock wall wart with the AW drag track at scale 1/4 mile?

How lowwww can I go and still have good power? Thanks

Jess
 

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yellar, therein lies your problem. the 4 ohm arm will work fine with the poly motor mags once you have enough amperage to push.
5 amps id probably fine for most applications, even 4 cars running side by side, but once you start using higher end motor parts the amperage must be increased.

don't know if true, but I remember in my youth hearing that a real V-8 had to make 500 HP in order to even use a blower(supercharger), so a lot of work had to go into the block, heads, intake etc before even considering bolting on a blower.

not a real good analogy, but, yeah, get a better power supply with more amperage to push those cars with custom wound arms and poly or neo magnets.
you might have to upgrade certain parts of the car, like putting braids on or in place of the pick up shoes. use springs in place of the motor brushes. apply shunts from the pickup(braid) shoes to the electrics on the chassis.

you see, .... 500 HP before you even use the blower!
 

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4 1 car, 5amps is plenty

My hot wind t-jets to 6 mag neo cars never pulled over 1/2 an amp unless there was a problem.

at startup they may pull more but that's for a few micro seconds.

but for circle racing

but drag racing?? I would think it would be close

so 5amps for 2 lanes should be no problem.

my 6mag inline unlimited cars would run 1/2 +/- an ohm arms with huge down force!! So a lot more power is needed to get those going and around the track than a non-mag car. and like I said, they are still under 1amp draw.

if my car was close to 1amp, it had a problem
 

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poly mags

I have a few different brands of the poly magnets. I have tried them in several different chassis with basically the same results.

Next, Im going to try them on a hotter car. I have one of Kipps hot double winds with advanced timing from about 15 years ago. This is in a car that already has poly magnets, so I will try a switcheroo and see what happens.

This car is very fast on my tracks, on the wall wart power and on the 5 amp power supply powered tracks. Soooo.... we will see.

Thanks to all who have answered.

Next question... are there any Central Pennsylvania guys on here who have their home tracks open for some drags and track racing? Maybe anyone within an hour or so of Northumberland/Schuykill County?

I have a half decent lock and joiner 4 laner and an AW drag strip. Im not running any organized racing, just for fun.

Jess
Shamokin, Pa.
 

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jess, contact tjetsgrig, you know who I mean, and get more specific ideas to get your polys on line.
 
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